Ronald Martinez/Getty ImagesMore than a dozen people were injured, some critically, after thousands of Oklahoma State football fans stormed the field for a wild victory celebration after the team defeated rival Oklahoma Saturday night.

STILLWATER, Okla. — Chaos erupted Saturday night after Oklahoma State's football team sealed a 44-10 victory over their archrival, Oklahoma, and the wild celebration turned from glee to gloom.

The victory prompted thousands of fans to storm the football field, where they tore down the goalposts, leaving at least 13 people injured, including two in critical condition, medical authorities said early today.

Michael Authement, who heads the command post at emergency medical provider LifeNet EMS, told the Associated Press that a throng so big took to the field as the game ended that some fans were trampled and one person fell at least 15 feet onto concrete during a wild celebration by Oklahoma State fans.

No. 13 Oklahoma State routed the Sooners on Saturday night to win the Big 12 championship and make its case to play for the BCS national title. The Cowboys (11-1, 8-1 Big 12) snapped an eight-game losing streak in the rivalry and won their first outright conference title since 1948 in the three-team Missouri Valley.

"They won the game and stormed the field and ripped down the goalposts and some were jumping off the stands and hit the field and others got trampled. It was a nasty deal," Authement said.

He said the crowd was so big it took police at least 45 minutes to clear fans from the field at Boone Pickens Stadium in Stillwater. "There were thousands of people. Thousands of people stormed the field. You couldn't move there were so many people," he added.

News media photographs showed fans climbing atop the yellow goalposts and tearing them apart amid a crush of people on the field. Scores of hands stretched out to pull down the goalposts during the celebration.

Authement said nine ambulances, including six from LifeNet, rushed 11 of the injured away and the two in critical condition were flown to Oklahoma City hospitals. He said he knew of leg fractures but didn't have any details on the extent of the injuries, though two of the 13 had minor injuries and were treated at the scene and released.

Lesser injuries included broken ankles, ankle sprains and back sprains, said Shyla Eggers, public relations director for Stillwater Medical Center, adding eight injured came to her hospital. She told AP that her hospital received six of the injured in ambulances, two in private vehicles and at least two of the patients have been admitted and would undergo surgery on broken ankles.

"Our staff that was on hand took care of it. They were just very busy," Eggers said. "Game day is always busy."

Ronald Martinez/Getty ImagesOklahoma State Cowboys fans hang on the goal post after a 44-10 win against the Oklahoma Sooners at Boone Pickens Stadium Saturday night in Stillwater, Oklahoma. The celebration turned ugly, with reports of 13 people injured, two critically.

She had no immediate details on the more serious injuries, saying two people were flown from the scene to hospitals in other cities in Oklahoma.

An Oklahoma State University police central dispatcher said she had no immediate details to release when contacted by AP and the public information officer did not immediately return messages seeking comment. Stillwater police and the Oklahoma highway patrol also had no immediate comment.

Authement said the fans began storming the field with about 20 seconds left in the game. He said he had reports of people falling and being trampled in the surge. "It lasted 45 minutes, I'm sure before they got the field cleared," he said.

He said he was handling game night duty when a magnitude-5.6 earthquake rocked central Oklahoma and the same stadium as fans departed minutes after Oklahoma State had beaten Kansas State.

The Nov. 5 quake, which could be felt as far away as Wisconsin, was the strongest in the state's history when it rattled players in the locker room and set the stadium press box rippling as the last of some 58,000 fans cleared out.